if you have shell access, or you can chroot i.e. from a jumpdrive boot, then just roll back the updates. all pacman updates are stored in /var/log/pacman.log and old packages are stored in /var/cache/pacman/pkg/
..or at least they are in vanilla arch
in the pacman log it's very clear, the pacman command is listed, and then a transaction started message, then each updated package is listed. should be fairly easy to roll back changes
..or at least they are in vanilla arch
in the pacman log it's very clear, the pacman command is listed, and then a transaction started message, then each updated package is listed. should be fairly easy to roll back changes